Article
Physics, Multidisciplinary
Bibhuti Bhusan Jena, Pushpendra Gupta, Sagarika Nayak, Abhisek Mishra, Antonio Azevedo, Haifeng Ding, Subhankar Bedanta
Summary: Switching magnetization with spin current via spin orbital torque is a novel approach towards energy-efficient spintronics. High spin-orbit coupling materials such as heavy metals are typically used to generate spin current through spin Hall effect. However, recent research has focused on replacing heavy metals with antiferromagnets as spin sinks. The bimetallic antiferromagnet Mn2Au, with its high Neel temperature and spin Hall angle, has attracted attention in this regard.
Article
Materials Science, Multidisciplinary
Arun Parthasarathy, Egecan Cogulu, Andrew D. Kent, Shaloo Rakheja
Summary: This study discusses the precession and stability of the Neel order of antiferromagnets subjected to spin torque, focusing on the requirements for in-plane and normal components of spin polarization. The precessional motion is described as a damped-driven pendulum with hysteresis, showing critical values and frequency dependencies on the spin current.
Article
Engineering, Electrical & Electronic
Xia Chen, Xiaohui Shi, Zeyu Zhang, Xiang Liu, Chao Jin, Wenbo Mi
Summary: The strain-tailored magnetic and electronic transport properties of flexible spin valves were investigated. Different magnetoresistance effects were achieved by varying the thickness of the materials. The flexible spin valves showed good magnetic stability even after multiple bending.
ACS APPLIED ELECTRONIC MATERIALS
(2022)
Article
Engineering, Electrical & Electronic
Fengxian Wang, Wei Shen, Mingming Tian, Qian Chen, Zhaocong Huang, Chaoxia Kou, Jian Liang, Jun Du, Ya Zhai
Summary: The magnetic dynamic behaviors of permalloy films capped with gadolinium were studied, with the effects of increasing Gd thickness decreasing the saturation magnetization and surface anisotropy constant while enhancing the Gilbert damping. The introduction of a copper insert at the interface suppressed these trends, attributed to antiferromagnetic coupling between Gd and Py near the interface caused by the magnetic proximity effect.
IEEE TRANSACTIONS ON MAGNETICS
(2021)
Article
Nanoscience & Nanotechnology
B. Kaiser, J. Ramberger, J. D. Watts, J. Dewey, Y. Zhang, C. Leighton
Summary: In order to increase the spin signal, we integrated high-spin-polarization Co-Fe alloy ferromagnetic injectors and detectors into Al-based non-local spin valves. Smooth, polycrystalline (110-textured), solid-solution body-centered-cubic Co75Fe25 films were generated by room-temperature deposition on amorphous substrates from an alloy target, characterized by various techniques. Integration into transparent-interface Al non-local spin valves resulted in a similar to 5-fold enhancement of the spin signal relative to Co, with temperature-independent current spin polarizations exceeding 60%. Comparisons with prior literature show that Co-Fe alloys offer a facile route to higher spin polarization and spin signals in non-local spin valves, with minimal barrier to adoption.
Article
Engineering, Mechanical
Lukas Schickhofer, Johannes Wimmer
Summary: Shock absorbers, also known as dampers, play a crucial role in ensuring the safety and comfort of passengers in vehicles by absorbing displacement changes. This study investigates the two most common types of shock absorber valves, the spring valve and the shim valve, in a typical motorcycle suspension system. The study explores the properties of the valve system under different flow directions and considers factors such as adhesion force and pressure losses. The findings demonstrate the importance of valve stability, optimization of spring properties, and the impact of key parameters on valve vibrations.
JOURNAL OF FLUIDS AND STRUCTURES
(2022)
Article
Physics, Applied
Jian Su, Wei He, Gang Li, He Bai, Z. Z. Zhu, Ying Zhang, Z. H. Cheng, J. W. Cai
Summary: The magnetic damping of the free layer in a spin valve is found to be significantly enhanced when the pinned layer partially reverses its magnetization direction, due to the stray field from domain walls in the pinned layer. This enhancement surpasses the effect of pumped spin current.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2021)
Article
Materials Science, Multidisciplinary
Jeremy Letang, Claudia de Melo, Charles Guillemard, Aymeric Vecchiola, Damien Rontani, Sebastien Petit-Watelot, Myoung-Woo Yoo, Thibaut Devolder, Karim Bouzehouane, Vincent Cros, Stephane Andrieu, Joo-Von Kim
Summary: This experimental study focuses on the vortex dynamics in magnetic nanocontacts based on pseudo spin valves comprising the Co2MnGe Heusler compound. By combining precise film growth and nanoindentation techniques, different types of spin-transfer induced dynamics related to different modes of the magnetic vortex configuration were observed, such as mode hopping, mode coexistence, and mode extinction, in addition to the usual gyration mode.
Article
Materials Science, Multidisciplinary
Xingyu Shen, Yi Ji
Summary: A linear relationship between the Kondo spin-relaxation rate and the Kondo momentum-relaxation rate was found, where the former remains nearly constant despite a tenfold variation of the latter among 20 devices. This surprising relationship can be explained by considering spin relaxation through overlapping Kondo screening clouds, supporting the physical existence of elusive Kondo clouds.
Article
Chemistry, Multidisciplinary
Yanfei Zhu, Lidan Guo, Jun Guo, Luyang Zhao, Chunyan Li, Xueying Qiu, Yang Qin, Xianrong Gu, Xiangnan Sun, Zhiyong Tang
Summary: Quantum-confined atomically precise metal nanoclusters (MNCs) are a new type of inorganic-organic hybrid semiconductor that have been widely used in chemical sensing, optical imaging, biomedicine and catalysis. Researchers have successfully designed and fabricated a spin valve (SV) based on MNCs, demonstrating remarkable magnetoresistance values and the ability to change the spin-dependent transport properties by altering the atomic structure of the MNCs.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Physics, Multidisciplinary
M. Cosset-Cheneau, L. Vila, G. Zahnd, D. Gusakova, V. T. Pham, C. Grezes, X. Waintal, A. Marty, H. Jaffres, J-P Attane
Summary: Experimental evidence of spin absorption orientation dependence in ferromagnetic materials is provided, facilitating the quantification of spin-mixing conductance. The obtained values suggest a limitation by the Sharvin conductance, challenging traditional models based solely on Larmor, transverse decoherence, and spin diffusion lengths.
PHYSICAL REVIEW LETTERS
(2021)
Article
Chemistry, Physical
Te Niu, Hongyang Li, Yuhang Wei, Zhanming Zhou, Ying Liu
Summary: A new multi-principal Al-Co-Ni-Cu alloy with high damping and good corrosion resistance was prepared. The effects of the Al content on the microstructure, damping properties, corrosion behavior, and mechanical properties of AlxCoNi2Cu (x = 0, 0.1, 0.3, and 0.5) alloys were studied. The Al0.5CoNi2Cu alloy exhibited a significant increase in internal friction and lower corrosion rate, demonstrating promising damping and corrosion resistance properties for marine applications.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
Article
Materials Science, Multidisciplinary
Shuling Sun, Bo Wang, Wangda Li, Xiaoxue Zeng, Yonghai Guo, Bo Han, Tao Wang, Dezheng Yang, Xiaolong Fan, Jiangwei Cao
Summary: This study investigates the spin-orbit torque (SOT) and unidirectional magnetoresistance (UMR) effect in a Co/Cu/Co structure. In addition to the harmonic terms from the fieldlike SOT, two different unidirectional harmonic signals are observed in angular and field scan measurements. By combining the SOT effective fields obtained from the harmonic Hall voltage measurement, the contributions of the observed unidirectional harmonic signals are successfully separated.
Article
Materials Science, Multidisciplinary
Quentin Remy
Summary: We propose an extension to simple s-d models to simulate ultrafast magnetization dynamics and spin transport in metallic heterostructures. We introduce an alternative spin dissipation channel caused by a finite exchange splitting of the s band and identify three different mechanisms governing the dynamics of spin accumulation. Based on our theory, we explain the subpicosecond reversal of a ferromagnet in rare-earth free spin valves and support the conclusion of J. Igarashi et al. favoring magnetization reversal due to the rotation of the spin polarization of a reflected spin current.
Article
Chemistry, Multidisciplinary
Neda Noei, Roberto Mozara, Ana M. Montero, Sascha Brinker, Niklas Ide, Filipe S. M. Guimaraes, Alexander I. Lichtenstein, Richard Berndt, Samir Lounis, Alexander Weismann
Summary: By studying the attachment of single cobalt atoms to monatomic copper chains, we have demonstrated the ability to control spin orientation through the atomic environment. This research has important implications for understanding low-energy excitations in nanostructures on surfaces and showcases the potential to manipulate atomic-scale magnetic moments, which can greatly impact quantum devices.
Article
Multidisciplinary Sciences
Abdulhakim Bake, Md Rezoanur Rahman, Peter J. Evans, Michael Cortie, Mitchell Nancarrow, Radu Abrudan, Florin Radu, Yury Khaydukov, Grace Causer, Karen L. Livesey, Sara Callori, David R. G. Mitchell, Zeljko Pastuovic, Xiaolin Wang, David Cortie
Summary: This article presents datasets of electron microscopy, polarised neutron reflectometry, and magnetometry for ultra-small cobalt particles in titania thin films. The provided data can assist in the development of advanced fitting algorithms for magnetization gradients in thin films.
Article
Nanoscience & Nanotechnology
Jin Hong Lee, Lourdes Marcano, Raphael Aeschlimann, Mohamad-Assaad Mawass, Chen Luo, Alexandre Gloter, Julien Varignon, Florin Radu, Sergio Valencia, Manuel Bibes
Summary: Epitaxial strain is applied to orthorhombic chromites to engineer their physical properties, particularly their antiferromagnetic spin order, which is strongly tunable by the applied strain. The orthorhombic chromites exhibit a higher dimensionless figure of merit compared to other perovskites, suggesting their potential use in energy-efficient piezo-spintronic devices.
Article
Materials Science, Multidisciplinary
V Ukleev, C. Luo, R. Abrudan, A. Aqeel, C. H. Back, F. Radu
Summary: Resonant elastic soft X-ray magnetic scattering (XRMS) is a powerful tool to explore long-periodic spin textures in single crystals. This research presents a method to overcome the limitations of momentum transfer range in XRMS studies by using specular reflection from a sub-nanometer smooth crystal surface. The results demonstrate the observation of spin modulations on the surface of a Cu2OSeO3 single crystal and the measurement of their chirality.
SCIENCE AND TECHNOLOGY OF ADVANCED MATERIALS
(2022)
Article
Instruments & Instrumentation
Nanna Zhou Hagstrom, Michael Schneider, Nico Kerber, Alexander Yaroslavtsev, Erick Burgos Parra, Marijan Beg, Martin Lang, Christian M. Gunther, Boris Seng, Fabian Kammerbauer, Horia Popescu, Matteo Pancaldi, Kumar Neeraj, Debanjan Polley, Rahul Jangid, Stjepan B. Hrkac, Sheena K. K. Patel, Sergei Ovcharenko, Diego Turenne, Dmitriy Ksenzov, Christine Boeglin, Marina Baidakova, Clemens von Korff Schmising, Martin Borchert, Boris Vodungbo, Kai Chen, Chen Luo, Florin Radu, Leonard Mueller, Miriam Martinez Florez, Andre Philippi-Kobs, Matthias Riepp, Wojciech Roseker, Gerhard Gruebel, Robert Carley, Justine Schlappa, Benjamin E. Van Kuiken, Rafael Gort, Laurent Mercadier, Naman Agarwal, Loic Le Guyader, Giuseppe Mercurio, Martin Teichmann, Jan Torben Delitz, Alexander Reich, Carsten Broers, David Hickin, Carsten Deiter, James Moore, Dimitrios Rompotis, Jinxiong Wang, Daniel Kane, Sandhya Venkatesan, Joachim Meier, Florent Pallas, Tomasz Jezynski, Maximilian Lederer, Djelloul Boukhelef, Janusz Szuba, Krzysztof Wrona, Steffen Hauf, Jun Zhu, Martin Bergemann, Ebad Kamil, Thomas Kluyver, Robert Rosca, Michal Spirzewski, Markus Kuster, Monica Turcato, David Lomidze, Andrey Samartsev, Jan Engelke, Matteo Porro, Stefano Maffessanti, Karsten Hansen, Florian Erdinger, Peter Fischer, Carlo Fiorini, Andrea Castoldi, Massimo Manghisoni, Cornelia Beatrix Wunderer, Eric E. Fullerton, Oleg G. Shpyrko, Christian Gutt, Cecilia Sanchez-Hanke, Hermann A. Durr, Ezio Iacocca, Hans T. Nembach, Mark W. Keller, Justin M. Shaw, Thomas J. Silva, Roopali Kukreja, Hans Fangohr, Stefan Eisebitt, Mathias Klaui, Nicolas Jaouen, Andreas Scherz, Stefano Bonetti, Emmanuelle Jal
Summary: The advent of X-ray free-electron lasers (XFELs) has revolutionized fundamental science, providing researchers with unprecedented brightness, coherence, and pulse duration. This paper presents the results from the first megahertz-repetition-rate X-ray scattering experiments at the Spectroscopy and Coherent Scattering (SCS) instrument of the European XFEL. The experimental capabilities offered by the SCS instrument, operating at a megahertz repetition rate and using a novel DSSC 2D imaging detector, are illustrated.
JOURNAL OF SYNCHROTRON RADIATION
(2022)
Article
Nanoscience & Nanotechnology
David Gandia, Lourdes Marcano, Lucia Gandarias, Danny Villanueva, Inaki Orue, Radu Marius Abrudan, Sergio Valencia, Irati Rodrigo, Jose Angel Garcia, Alicia Muela, Ma Luisa Fdez-Gubieda, Javier Alonso
Summary: The influence of culture medium on the structural, morphological, and magnetic characteristics of Magnetospirillum magneticum AMB-1 magnetosome chains has been investigated. The introduction of Co ions in the MSGM + W bacteria affects the magnetic response and increases coercivity and remanence. The heating efficiency of these bacteria is also influenced by the culture medium, with MSGM - W bacteria being the most efficient below 35 mT, and FSM and MSGM + W bacteria being the most efficient above 60 mT, reaching a maximum SAR of 12 W g(-1).
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Materials Science, Multidisciplinary
Yu-Hong Lai, Pao -Wen Shao, Chang-Yang Kuo, Cheng-En Liu, Zhiwei Hu, Chen Luo, Kai Chen, Florin Radu, Yong-Jyun Wang, Junding Zheng, Chungang Duan, Chun-Fu Chang, Li Chang, Yi-Chun Chen, Sang-Wook Cheong, Ying-Hao Chu
Summary: This study investigates the modulation of magnetic and electric orders in magnetoelectric materials through quasi-static mechanical strain. It is found that mechanical bending can significantly enhance the magnetization of Cr2O3 film and adjust its electric polarization and magnetoelectric coupling. This work provides a comprehensive understanding of the relationship between strain and magnetic and electrical behaviors and opens new possibilities for combining magnetoelectric materials with flexible substrates.
Article
Chemistry, Physical
K. Chen, C. Luo, Y. Zhao, F. Baudelet, A. Maurya, A. Thamizhavel, U. K. Roessler, D. Makarov, F. Radu
Summary: In rare-earth compounds, the proximity of the 4f level to the Fermi energy leads to instabilities of the charge configuration and the magnetic moment. We provide experimental evidence for induced magnetic polarization of the Eu3+ atomic shell due to interactions with the Eu2+ atomic shell. Applying external pressure leads to a transition from antiferromagnetic to fluctuating behavior in EuNiGe3 single crystals, with observed magnetic polarization for both Eu2+ and Eu3+ valence states.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2023)
Article
Chemistry, Multidisciplinary
Berthold H. H. Rimmler, Binoy H. K. Hazra, Banabir Pal, Katayoon Mohseni, James M. M. Taylor, Amilcar Bedoya-Pinto, Hakan Deniz, Malleswararao Tangi, Ilya Kostanovskiy, Chen Luo, Robin R. R. Neumann, Arthur Ernst, Florin Radu, Ingrid Mertig, Holger L. L. Meyerheim, Stuart S. P. Parkin
Summary: Antiferromagnets with non-collinear spin structures have attractive properties for spintronic devices, such as anomalous Hall effect and spin Hall effect. However, these effects can only be observed in a single antiferromagnetic domain state, which requires perturbation of the compensated spin structure through spin canting. This study reveals that spin canting in Mn3SnN and Mn3GaN is induced by structural symmetry lowering caused by large displacements of magnetic manganese atoms.
ADVANCED MATERIALS
(2023)
Article
Physics, Multidisciplinary
T. Ferte, M. Beens, G. Malinowski, K. Holldack, R. Abrudan, F. Radu, T. Kachel, M. Hehn, C. Boeglin, B. Koopmans, N. Bergeard
Summary: The laser induced ultrafast quenching of Gd 4f magnetic order in Co100-xGdx alloys was studied to understand the role of the Co 3d-Gd 5d inter-atomic exchange coupling. X-ray Magnetic Circular Dichroism spectroscopy was performed using ultrashort soft X-ray pulses at the BESSY II synchrotron radiation source. The results showed that the time scales for the laser induced quenching of Gd 4f magnetic order differed for different Co-Gd alloys. The magnetic losses mainly occurred within the first picosecond while the electron distribution was out of equilibrium, and then occurred at slower rates influenced by the alloy composition.
EUROPEAN PHYSICAL JOURNAL-SPECIAL TOPICS
(2023)
Article
Chemistry, Physical
Alevtina Smekhova, Alexei Kuzmin, Konrad Siemensmeyer, Chen Luo, James Taylor, Sangeeta Thakur, Florin Radu, Eugen Weschke, Ana Guilherme Buzanich, Bin Xiao, Alan Savan, Kirill V. V. Yusenko, Alfred Ludwig
Summary: The study investigates the structural, electronic, and magnetic properties of a high-entropy alloy using multi-edge X-ray absorption spectroscopy. The researchers reveal the local crystallographic ordering and component-dependent lattice displacements, as well as the oxidation states, electronic structure, and magnetic behavior of the alloy on the surface and in the sub-surface volume of the film. The study also evaluates the magnetic moments of Fe, Co, and Ni components.
Article
Physics, Multidisciplinary
Maryam Sajedi, Chen Luo, Konrad Siemensmeyer, Maxim Krivenkov, Kai Chen, James M. Taylor, Marion A. Flatken, Florin Radu, Oliver Rader
Summary: Lead halide perovskites are new key materials with various applications. Recent reports suggest that doping with Mn can lead to ferromagnetism, but our study shows that significant double exchange and ferromagnetism do not occur in Mn-doped lead halide perovskite thin films. Our results indicate that Mn is not suitable for creating ferromagnetism in lead halide perovskites.
COMMUNICATIONS PHYSICS
(2023)
Article
Physics, Multidisciplinary
Chen Luo, Kai Chen, Victor Ukleev, Sebastian Wintz, Markus Weigand, Radu-Marius Abrudan, Karel Prokes, Florin Radu
Summary: In this study, the authors investigate the magnetic domain walls of ferrimagnetic skyrmions in DyCo3 using scanning transmission X-ray microscopy (STXM) and X-ray magnetic linear dichroism (XMLD). They find that the domain walls of ferrimagnetic skyrmions in this material are of the Neel type. Micromagnetic simulations support these findings and provide insights into the nature of the Dzyaloshinskii-Moriya interaction (DMI) in ferrimagnetic systems, contributing to our understanding of control over chiral spin texture in these materials.
COMMUNICATIONS PHYSICS
(2023)
Article
Physics, Multidisciplinary
Priya R. Baral, Oleg I. Utesov, Chen Luo, Florin Radu, Arnaud Magrez, Jonathan S. White, Victor Ukleev
Summary: This study investigates the role of anisotropic exchange interaction (AEI) in the formation of tilted conical and disordered skyrmion states in the chiral magnet Cu2OSeO3. Using muon scattering and temperature dependence measurements, it is found that the AEI continuously increases below 50 K, leading to a 10% variation in the conical spiral pitch. These findings contribute to the understanding and design of various spiral states in chiral magnets.
PHYSICAL REVIEW RESEARCH
(2023)
Article
Materials Science, Multidisciplinary
Alexei Nefedov, Chun Li, Kai Mueller, Anemar Bruno Kanj, Lars Heinke, Chen Luo, Kai Chen, Florin Radu, Evangelos Golias, Wolfgang Kuch, Christof Woell
Summary: Metal-organic frameworks (MOFs) are crystalline and porous, molecular solids consisting of metal nodes and organic ligands. In this study, the magnetic properties of two SURMOF-2 systems (Cu(bdc) and Cu(bpdc)) were investigated using x-ray magnetic circular dichroism. The presence of the ferromagnetic phase in these SURMOF-2 systems was confirmed. The magnetic behavior of the guest molecules differed from that of the host matrix after loading.
Article
Materials Science, Multidisciplinary
A. Rauguth, A. Alhassanat, H. Elnaggar, A. A. Athanasopoulou, C. Luo, H. Ryll, F. Radu, T. Mashoff, Frank M. F. de Groot, E. Rentschler, H. J. Elmers
Summary: This study investigates the molecular structure and properties of heterometallic metallacrown-4 complexes using x-ray magnetic circular dichroism spectra. The results show an anisotropic charge distribution of rare-earth ions in a tetragonal crystal field, with a significant contribution of orbital moment to the magnetic moment of the molecule.
